Automatic Room Lights Controller Using Arduino and PIR Sensor

Automatic room lights controller can be installed in which the room lights will turn on automatically upon detection of human motion and will stay tuned until the motion stops or the person has left the room. Such type of system can be implemented where we don’t require continuous light supply but only when a person is present. The common places where we can install the system are washrooms, bathrooms, office rooms, classrooms in schools and colleges, garages, etc. Also, using this controller system, we don’t need to worry about electricity as the room lights will switch off on their own when no person is present. A huge amount of energy and economy will also be saved . The main components of the Automatic Room Lights project are Arduino Uno, PIR Sensor and the Relay Module. Keywords: Arduino Uno, Lights, PIR sensor, Relay Module

Greenhouse Monitoring Using IOT

Agriculture plays vital role in the economic of developing country. This paper Proposes, monitoring and access control system for greenhouse by using IOT. Our Proposed system will check for certain common conditions, for instance such as moistness, soil condition, temperature, humidity, light intensity, Carbon monoxide detection and operate the water supply through phone itself. All the environmental instance information are send to cloud server using Wi-Fi module ESP32. If any climatic condition crosses certain specific threshold limit related action will be taken place like if the temperature becomes high the rooftop of the green house will be opened or the exhaust fan will be switch ON manually by the user and if the light intensity goes down the external light supply will be given to the plants. The microcontroller will turn ON the motor if the moisture content of soil doesn’t meet the required condition. The sensors used in the proposed system are Resistive soil moisture sensor, DHT11 sensor, MQ9 sensor and LDR. The user can monitor and control parameters through mobile phone by using BLYNK app. This model was attempted in order to achieve the intelligent monitoring of greenhouse environment parameters like temperature, humidity, soil moisture etc., keeping the user continuously informed of the conditions inside the greenhouse using IOT technology.

Sistemas de fotoativação e seus impactos nas restaurações em resina composta: uma revisão de literatura

Photoinitiating substances and photoactivation devices are directly conected to the physical-mechanical and chemical performance of the composite resins. Due to the yellowish coloration from camphorquinone (CQ), alternative photoinitiators have been used in a complementary or substitute way. Thus, the objective of the study was to develop a literature review on photoinitiators in correlation with photoactivation and its impacts on composite resin restorations. The literature review has been conducted based on researches in the Scielo, PubMed and Google Scholar databases through the descriptors: composite resins, polymerization and photoinitiators. In the search carried out between March and June 2020, of the forty-two articles found, thirty-seven articles were used. Among the variations of the photoinitiator systems, it's been observed that in general, they presented positive points such as good physical-mechanical and chemical performance with the evaluation of the degree of conversion, flexural strength and microhardness. They also presented negative points such as high toxicity, gap formation and unsatisfactory indices of microleakage in dentin. In relation to photoactivation systems, light emitting diodes (LEDs), called polywave, brought advantages by emitting a larger wave spectrum that reaches the violet color, necessary to activate the polymerization chemical reaction of the alternative photoinitiators. It can be concluded that the emergence of new photoinitiating substances and polywave devices establish a certain harmony with the light supply capacity, the reaction of the substances and the reach of the physical-mechanical properties provided by them.

CO2 stimulation and response mechanisms vary with light supply in boreal conifers

Aims Black spruce (Picea mariana [Mill.] B.S.P.) and white spruce (Picea glauca [Moench] Voss.) are congeneric species. Both are moderately shade tolerant and widely distributed across North American boreal forests. Methods To understand light effects on their ecophysiological responses to elevated [CO2], 1-year old seedlings were exposed to 360 and 720 µmol mol -1 [CO2] at three light conditions (100, 50 and 30% of full light in the greenhouse). Foliar gas exchanges were measured in the mid- and late-growing season. Important Findings Elevated [CO2] increased net photosynthesis (Pn) and photosynthetic water use efficiency, but it reduced stomatal conductance and transpiration. The stimulation of photosynthesis by CO2 was greatest at 50% light and smallest at 100%. Photosynthesis, maximum carboxylation rate (Vcmax) and light saturated rate of electron transport (Jmax) all decreased with decreasing light. Elevated [CO2] significantly reduced Vcmax across all light treatments and both species in mid-growing season. However, the effect of elevated [CO2] became insignificant at 30% light later in the growing season, with the response being greater in black spruce than in white spruce. Elevated [CO2] also reduced Jmax in white spruce in both measurements while the effect became insignificant at 30% light later in the growing season. However, the effect on black spruce varied with time. Elevated [CO2] reduced Jmax in black spruce in mid-growing season in all light treatments and the effect became insignificant at 30% light later in the growing season, while it increased Jmax later in the season at 100% and 50% light. These results suggest that both species benefited from elevated CO2, and that the responses varied with light supply, such that the response was primarily physiological at 100% and 50% light, while it was primarily morphological at 30% light.

Effects of gradual and sudden changes of salinity and light supply for astaxanthin production in Haematococcus pluvialis (Chlorophyceae)

Astaxanthin, a carotenoid naturally synthesized by Haematococcus pluvialis, is economically important for the nutraceutical, pharmaceutical and food industries due to its high antioxidant and anti-inflammatory properties. We investigated astaxanthin accumulation in H. pluvialis after stepwise versus suddenly increased light supply and salt (NaCl) concentrations. Light was increased from 75 to 150, and then to the final intensity of 350 μmol photons m –2 s–1 in three-day intervals. The effect of gradually increased salt concentration was examined with two steps from 0.2 to the final concentration of 0.8 % (w/v) in three-day intervals. The overall induction period for astaxanthin accumulation was 13 days. Out of all treatments, stepwise increased light supply resulted in highest cell viability and highest astaxanthin accumulation with 15.76 ± 0.88 mg g –1 dry mass. It is an energy-saving, appropriate strategy to achieve optimal astaxanthin accumulation. It moreover resulted in the least biomass loss, which is caused by the provided stress conditions.

The Effect of Light Wavelength on CO2 Capture, Biomass Production and Nutrient Uptake by Green Microalgae: A Step Forward on Process Integration and Optimisation

Microalgae have drawn the attention of several researchers as an alternative to the traditional physicochemical CO2 capture methods, since they can convert CO2 and water into organic matter and release oxygen into the atmosphere. Microalgal growth can be improved by changing light supply, such as light intensity, wavelength, and photoperiod. In this study, the effect of different light wavelengths on CO2 capture, nutrient removal from a synthetic effluent and biomass production of Chlorella vulgaris, Tetradesmus obliquus and Neochloris oleoabundans was studied. The experiments were conducted with light-emitting diodes (LEDs) with different wavelengths: 380–750 nm (white), 620–750 nm (red) and 450–495 nm (blue). The maximum specific growth rate was obtained by N. oleoabundans with white LEDs (0.264 ± 0.005 d−1), whereas the maximum biomass productivity (14 ± 4 mgdw L−1 d−1) and CO2 fixation rate (11.4 mgCO2 L−1 d−1) were obtained by C. vulgaris (also with white LEDs). Nitrogen and phosphorus removal efficiencies obtained under white light conditions were also the highest for the three studied microalgae.